Question Bank

Class : IX CBSESubject : Physical Science

Topic : MOTION

Very Short Answer Questions

01.Define the term ‘displacement’. Is it a vector quantity or a scalar quantity?

02.Define the term ‘distance’. Is it a vector quantity or a scalar quantity?

03.The displacement of a body can never be greater than the distance covered by a body. Is the statement true or false?

04.Can a body have zero velocity and still acceleration? Give example.

05.What is the nature of distance time graph for uniform motion of an object?

06.What is the acceleration of a freely falling body?

07.What is the acceleration of a body moving with uniform velocity?

08.What does the slope of a distance-time graph gives?

09.What does the area of a velocity-time graph gives?

10.Give two examples of vector quantities.

Short Answer Questions

11.A body is moving along a circular path of radius R. What will be the distance and displacement of the body when it completes half a revolution?

12.An ant travels a distance of 8 cm from P to Q and then moves a distance of 6 cm at right angles to PQ. Find the resultant displacement?

13.Define Scalar quantities and Vector quantities?

14.Define the term “uniform acceleration”. Give one example of a uniformly accelerated motion.

15.Define the term ‘acceleration’. Is it a vector quantity or a scalar quantity?

16.Distinguish between speed and velocity.

17.Arrange the following speeds in increasing order (keeping the least speed first):

  1. An athlete running with a speed of 10 m/s
  2. A bicycle moving with a speed of 200m/min
  3. A scooter moving with a speed of 30km/h.

18.A bullet initially moving with a velocity of 20m/s strikes a target and comes to rest after penetrating a distance of 0.01m in the target. Calculate the retardation produced by the target.

19.A body moving in a straight line at 72kmph undergoes an acceleration of 4m/s2. Find its speed after 2 seconds.

20.A car acquires a velocity of 72 kmph in 10 seconds starting from rest. Find (a) the acceleration, and (b) the average velocity.

Long Answer Questions

21.What is motion? What are types of motion? Define them with one example each.

22.Derive the relation s = ut + ½ at2

23.Write the SI units of Displacement, velocity and acceleration?

24.Define the terms “average speed” and “uniform speed”.

25.Write the three equations of uniformly accelerated motion. Give the meaning of each symbol which occurs in them.

26.Write the equations of motion in the case of a freely falling body.

27.Define the terms (a) Time of flight(b) Maximum heightand (c) Range

28.Write the expressions for (a) time of flightand (b) maximum height

29.A vertically projected body takes 5 seconds to reach the point of projection. What is the time of ascent and what is the maximum height reached by the body?

30.A body is thrown vertically upwards with a velocity 19.6 m/s. What is the maximum height reached by the body and what is the time of flight? (take g = 9.8 m/s2)

Topic : Force and Newton’s laws of motion

Very Short Answer Questions

01.What type of forces – balanced or unbalanced – act on a rubber ball when we press it between our hands?

02.What is the usual name of the force which cannot produce motion in a body but only change its shape?

03.Name the unbalanced force which slows down a moving bicycle when we stop pedaling it.

04.Explain the law of inertia.

05.When a carpet is beaten with stick dust comes out of it. Why?

06.State Newton’s I Law of motion.

07.Define momentum. Give its S.I. unit.

08.______is a measure of the inertia of a body.

09.Explain why, a cricket player moves his hands backwards while catching a fast moving cricket ball.

10.Momentum of a body depends on ______and ______.

Short Answer Question

11.What do you understand by the terms ‘balanced forces” and “unbalanced forces”? Explain with examples.

12.On what factors does the inertia of a body depend? Which has more inertia, a cricket ball or a rubber ball of the same size?

13.A force of 5N gives a mass m1 and acceleration of 8m/s2 and mass m2 and acceleration of 24 m/s2. What acceleration would it give if both masses are tied together?

14.A cricket ball of mass 100g moving with a speed of 30m/s is brought to rest by a player in 0.03s. Find the change of momentum of the ball and force applied by the player.

15.What is friction? Friction is due to the ______of surface.

16.Two bodies A and B of same masses are moving with velocities ‘v’ and ‘2v’ respectively. Find the ratio of their (i) inertia (ii) Momentum

17.What is the unit of force? Give its definition.

18.How long will it take a force of 10 N to stop a mass of 2.5 kg which is moving at 20 m/s ?

19.Explain the term “impulse of a force”. Write its SI unit.

20.Name the principle on which a rocket works. Explain the principle.

Long Answer Questions

21.A bullet of mass 0.001 kg is fired from a gun of mass 2 kg. If the velocity of the bullet be 72kmph, calculate the recoil velocity of the gun?

22.Two marbles of masses 40gm and 60gm moving in the same direction with velocities 4m/s and 6m/s on a table undergoes elastic collision. With what velocity do they move if they stick together after collision?

23.State Newton’s II Law. Derive the mathematical expression for the same.

24.State Newton’s III Law.Write down the action and reaction forces in the following cases

(a) a book lying on a table (b) firing of bullet from a gun

25.Do action and reaction act on the same body or different bodies? How are they related in magnitude and direction?

26.A 2000 kg car traveling at 72 kmph ran into a concrete wall and stopped in 0.05 sec. What impulse did the wall exert on the car?

27.An unloaded truck weighing 2000 kg has a maximum acceleration of 0.5 m/s2. What is the maximum acceleration when it is carrying a load of 2000 kg?

28.If you apply some force for moving forward on earth, but earth exerts the same opposite force on you, then how do you move?

29.A rifle bullet of mass 7 gm leaves the barrel of rifle with a velocity of 300 m/s. If the rifle recoils with a velocity of 1 m/s, find the mass of the rifle?

30.State and prove law of conservation of momentum.

Topic: Matter in Our Surroundings

Very Short answer Questions

  1. Define matter. Give four examples of matter.
  2. Which single term is used to describe the mixing of copper sulphate and water kept in a beaker, on its own?
  3. In a beam of sunlight entering a room, we can sometimes see dust particles moving in a haphazard way in the air. Why do these dust particles move?
  4. When an incense stick (agarbatti) is lighted in one corner of a room, its fragrance spreads in the whole room quickly. Which characteristic of the particles of matter is illustrated by this observation?
  5. What is the scientific name of particles which make up matter?
  6. What is the physical state of water at (i) 250 K (ii) 2500C
  1. Convert the following temperatures to the Celsius scale.

a) 293 Kb) 470 K

  1. Define latent heat of vaporisation.
  2. What will be the effect of change of pressure on the state of a matter?
  3. Define ‘melting point of a substance’? What is the melting point of ice?

Short Answer Questions

  1. Explain the factors which affect the rate of evaporation.
  2. Give reasons:

a) the rate of diffusion of liquids is higher than that of solids

b)Steam produces more severe burns than boiling water.

  1. Which produces more severe burns: boiling water or steam? Why?
  2. Why should we wear cotton clothes in summer?
  3. Give two reasons to justify that:

a)Water is a liquid at room temperature.

b) An iron almirah is a solid.

  1. Write the full forms of the following:
  2. LPGb. CNG
  3. What is diffusion? Which diffuse faster: a liquid or a gas?
  4. Why is ice at 273 K more effective in cooling than water at the same temperature?
  5. What is sublimation? Name two substances which undergo sublimation?
  6. What factors are responsible for the change in state of solid carbondioxide when kept exposed to air?

Long Answer Questions

  1. Compare the properties of solids,liquids and gases in tabular form?
  2. What are the characteristics of matter?
  3. What do you understand by the term ‘latent heat’? What are the two types of latent heat?
  4. Which contain more heat, 1 kg of water at 1000C or 1 kg of steam at 1000C? Give reason for your answer.
  5. Draw the ‘states of matter triangle’ to show the interconversion of states of matter.
  6. How will you demonstrate that water vapour is present in air?
  7. Explain the following:
  8. Why do gases have neither a fixed shape nor a fixed volume?
  9. A sponge can be compressed easily, so why do we call sponge a solid?
  10. Why latent heat does not cause a rise in temperature of the substance?
  11. Why the temperature of boiling water does not rise even though heat is given continuously?
  12. What properties of particles decide whether a given substance will exist as a solid, a liquid or a gas?

Topic : Is Matter Around Us Pure

Very Short answer Questions

  1. How would you confirm that a colourless liquid given to you is pure water?

2. Which method can be used to separate

a. mixture of naphthalene & common salt b. iron pins from sand

3. A solution contains 50 g of common salt and 400 g of water. Calculate the concentration in terms of mass percentage of the solution?

  1. What is the difference between mixture and compound?
  2. What is colloid? What are its properties?
  3. What is an element? Write down the names of four elements.
  4. What are metalloids? Give two examples.
  5. Define mixture. What are the different types of mixtures?
  6. What is the difference between a suspension and a colloid?
  7. Define solubility of a substance. How does it vary with temperature?
  8. Milk is a______solution but vinegar is a ______solution.
  9. What is the concentration of a solution which contains 2.5 gm of salt dissolved in 50 gm of water?
  10. What is meant by sublimation?
  11. What are the methods to separate a mixture of two solids?
  12. Write any four methods to separate a mixture of solid and a liquid?

Short Answer Questions

  1. Write the steps you would use for making tea. Use the words solution, solvent, solute, dissolve, soluble, insoluble, filtrate and residue.
  2. Explain the following giving examples.

a)saturated solution

b)pure substance

c)suspension

  1. Which of the following are chemical changes?

a) growth of a plantb) Rusting of iron c) Mixing of iron fillings and sand d) Cooking of food e) Digestion of food f) Freezing of water g) Burning of a candle.

  1. Which of the following will show “Tyndall effect”?

a) Salt solutionb) Milkc) Copper sulphate solutiond) Starch solution

  1. Classify each of the following as a homogeneous or heterogeneous mixture.

Soda water, wood, air, soil, vinegar, filtered tea.

  1. Write any four differences between metals and non-metals.
  2. Write any four differences between mixtures and Compounds.
  3. Write any two properties of solution and suspension.
  4. What are the different types of colloids?
  5. What are the effects of temperature and pressure on solubility?

Long Answer Questions

  1. What are the differences between physical change and chemical change?
  2. What are pure and impure substances? Write their properties.
  3. Pragya tested the solubility of three different substances at different temperatures and collected the data as given below (results are given in the following table, as grams of substance dissolved in 100 gm of water to form a saturated solution).

Substance Dissolved / Temperature in Kelvin
283 / 293 / 313 / 333 / 353
Solubility
Potassium nitrate / 21 / 32 / 62 / 106 / 167
Sodium chloride / 36 / 36 / 36 / 37 / 37
Potassium chloride / 35 / 35 / 40 / 46 / 54
Ammonium chloride / 24 / 37 / 41 / 55 / 66

a)What mass of Potassium nitrate would be needed to produce a saturated solution of potassium nitrate in 50 gm of water at 313 k?

b)Pragya makes a saturated solution of potassium chloride in water at 353 k and leaves the solution to cool at room temperature. What would she observe as the solution cools? Explain.

c)Find the solubility of each salt at 293K. Which salt has the highest solubility at this temperature?

d)What is the effect of change of temperature on the solubility of a salt?

  1. Classify the following into elements, compounds and mixtures.

a) Sodiumb) Soilc) Sugar solutiond) Silvere) Calcium carbonate f) Tin g) Silicon h) Coal i) Air j) Soap k) Methane l) Carbon dioxide m) Blood

  1. a. Which of the two solutions scatter light – soap solution or sugar solution?
  1. Draw the schematic representation of the water purification system

31. a. Which method will you employ to obtain pure ammonium chloride when it contains

potassium chloride as impurities.

b. Draw the experimental setup for the separation of two immiscible liquids. Mention 2

applications of it.

32. How is water purified & supplied on a large scale at water works? Explain with diagram.

33. Which separation technique will you apply for the separation of the following?

a)Sodium chloride from its solution in water

b)Ammonium chloride from a mixture containing sodium chloride and ammonium chloride.

c)Small pieces of metal in the engine oil of a car.

d)Different pigments from an extract of flower petals.

e)Butter from curd.

f)Oil from water.

g)Tea leaves from Tea.

h)Wheat grains from husk.

Topic : Gravitation

Very Short answer Questions

  1. What is the value of gravitational constant ‘G’?
  2. Write down the S.I. units of ‘g’ and ‘G’?
  3. State whether the following statement is true or false:

The force of gravitation between two objects depends on the nature of medium between them.

  1. Does the acceleration produced in a freely falling body depend on the mass of the body?
  2. What is the value of ‘g’ at the centre of the earth?
  3. What is the weight of an object on the surface of a moon?
  4. Relative density of iron is 125. What is its density in S.I units?
  5. State Archimedes principle.
  6. Define thrust.
  7. Explain why it is easy to swim in sea water than in pure water?

Short answer Questions

  1. Express universal law of gravitation mathematically? What Is its importance?
  2. Consider a planet whose radius and mass were half that of earth. What will be the value of acceleration due to gravity at its surface?
  3. Write the S.I. units of (i) pressure (ii) relative density
  4. The earth attracts the moon. Does moon attract the earth? If so, why does earth does not move towards the moon.
  5. A man weighs 686N on earth. What would be his mass and weight on moon?
  6. Can a body have mass but no weight? Give reason for your answer?
  7. What do you understand by the term “weightlessness”? When do we feel “weightlessness”?
  8. When a cricket ball is thrown vertically upwards, it reaches a maximum height of 5 metres.

(a)What was the initial speed of the ball?

(b)How much time is taken by the ball to reach the highest point?

  1. Define the terms density and relative density.
  2. What are the applications of Archimedes’ Principle?

Long answer Questions

  1. State universal law of gravitation? Derive the relation to find the force between 2 objects placed at distance “r”?
  2. What is relative density of a substance? Relative density of silver is 10. 8 g. the density of water is 1000kg/m³. What is the density of silver in SI unit?
  3. What is buoyant force? What is buoyancy? Give two factors on which it depends.
  1. The acceleration due to gravity at the surface of the moon is 1.67 m/s2. If the radius of the moon be 1.74x106m, calculate the mass of the moon. (Given G = 6.67x10–11 Nm2kg-2).

5. (a) Distinguish between mass and weight.

(b) Calculate the mass of an object whose weight is 49 N.

(c) A nail made of iron sinks in water but a cork floats on it. Why?

6. What are the differences between ‘g’ and ‘G’?

7. Why the value of g is maximum at poles and minimum at equator?

8. If a man weighs 60 kg on earth, how far must he go from the centre of the earth so that he weighs 30 kg? (Radius of the earth is 6400 km).

9. State the principle of flotation. When does an object float or sink when placed on the surface of a liquid?

10. State and explain Kepler’s laws of planetary motion.

Topic : Work and Energy

Very Short answer Questions

  1. Is work a scalar or a vector quantity?
  2. What should be the angle between the direction of force and the direction of motion of a body so that the work done is zero?
  3. Define the term watt.
  4. By how much the kinetic energy of a body increase if its speed is doubled?
  5. What is the energy possessed by a flying bird?
  6. How is energy stored in a clock?
  7. What do you understand by the term “transformation of energy”?
  8. State law of conservation of energy.
  9. What kind of energy transformations take place at a hydroelectric power station?
  10. Give the relation between kinetic energy and momentum.

Short answer Questions

  1. Define the term work. What is its S.I unit?
  2. How much is the mass of a man if he has to do 2500 J of work in climbing a tree 5 m tall? ( g = 10 ms-2) .
  3. Is it possible that a force is acting on a body but still the work done is zero? Give one example.
  1. Define power and give its unit.
  2. Define the term “energy” of a body. What is the unit of energy?
  3. What are the S.I and C.G.S units of energy? Give the relation between them.
  4. 1 H.P = ______watt, 1KWH = ______Joule.
  5. Two masses of 1gm and 9 gm are moving with equal KE’s. Find the ratio of the magnitudes of their respective linear momentum.
  6. Calculate the K.E. of a body of mass 2 Kg moving with a velocity of 0.1 m/s.
  7. On what factors does the K.E. of a body depend?

Long answer Questions

  1. a. What is the relation between S.I. unit and commercial unit of energy?

b. Derive the mathematical expression for kinetic energy.

c. Calculate the power of pump which can lift 100kg of water to store it in a water tank 19 m high in 25 seconds? (Use g=10m/s2)

2.What are the different types of Work? Explain with an example.

3.Derive the mathematical expression for P.E.

4.What are the different forms of energy?

5.How much work should be done on a bicycle of mass 20kg to increase its speed from 2 ms-1 to 5 ms-1?

6.Is potential energy is a vector or a scalar quantity? On what factorsdoes the gravitational P.E. of a body depends?

7. A man is instructed to carry a package from the base camp at B to summit A of a hill at a height of 1200 metres. The man weighs 800 N and the package weighs 200 N.

(i) How much work does man do against gravity?

(ii) What is the potential energy of the package at A if it is assumed to be zero at B?

  1. An electric bulb consumes 7.2 kJ of electrical energy in 2 minutes. What is the power of the electric bulb?
  2. Five electric fans of 120 watt each are used for 4 hours. Calculate the electrical energy consumed in kilowatt-hours.
  3. Explain the energy transformations that take place at hydroelectric power station?

Topic : Sound

Very Short answer Questions

  1. What is sound? What type of waves are sound waves in air?
  2. What type of wave is represented by displacement – distance graph?
  3. What is the frequency of a sound wave whose time-period is 0.05 Sec?
  4. Calculate the speed of a sound wave whose frequency is 2 kHz and wavelength 65 cm.
  5. What is the name of the strings which vibrate in our voice box when we talk?
  6. State whether the following statement is true or false:

Sound produced by a vibrating body travels to our ears by the actual movement of air.